Invitation PHP for Portal SugarCRM

Hello, I'm looking for a complete script/website that can be integrated into SugarCRM or completed in a portal technology that can be deployed in Linux LAMP architecture. The site and script needs to have the same functionality of [login to view URL] where users can create an account and be able to invite people to a party or a paid event, then have them track the RSVPs and send followup information. The script should allow for admin control of the types of events that the user can send invitations too. For instance, we want the user to be able to invite to a birthday party, reunion, etc (admin creates the list) has options of what will be offered and a price list for attending will show depending on the selections. This should all be adjustable by the admin. The user should also be allowed to set the cost of the invitation to $0, meaning that the user will incur all costs and will be charged for each person that attends. The person receiving the invitation will be able to respond, pay for the invitation if they want to go and send messages, etc. just like the evite dot com. The script should integrate with SugarCRM or maintain a list of members with the DB that can be accessed by a CRM solution. Not sure exactly what other features will need to be addressed, but if it is similar to evite dot com, then it should be sufficient. If you can integrate it completely into SugarCRM Community Edition 5.0 - that would be best. Thanks!